Transmitter for wireless telegraphy.



o. 851,336. PATENTED APR. 23-, 1907. G. VON ARGO.

TRANSMITTER FOR WIRELESS TELBGRAPHY. APPLICATION FILED JUNE 27, 1905.

m STATES ATEN'I orrion.

GEO-RG VON ARGO, OF BERLIN, GERMANY.

TRANSMITTER FOR WIRELESS TELEGRAPHY.

Specification of Letters Patent.

Patented April 23, 1907.

Application filed June 27, 1905. Serial No. 268,009.

To ZN/"whom it may concern.-

Be it known that I, GEoRe GRAF voN ARGO, a subject of the King of Prussia, residing at Berlin, Germany, have invented certain new and useful Improvements in Transmitters. for l/Vireless Telegraphy, of which the following is a full, clear, and exact description.

In practical exchange of messages between tions may not find-time to deliver an underv standable message.

In transmitter arrangements hitherto known, the method pursued was to tune the recelvmg aerial conductor first by means of a detector which responded to variations of amplitude of the waves, and to ascertain the wave lengths of the foreign transmitter from the hereby resulting dimensions, of the'seltinduction coils and condenser; then the transmitter of the home station was tuned to the same wave lengths with the assistance of an ordinary wave meter.

For this a double tuning is thus necessary, firstly that of the home receiver and .then that of the home transmitter, and this method necessitated a greatwaste of time.

Now this invention relates to an arrangement of transmitter 1 in which one manipulation is omitted, and the home transmitter is directly tuned by means of a detector connected therewith. The transmitter may then be immediately used for dispatching the ascertained wave, after this detector has been switched oil.

In the present invention it is of importance that no deleterious or impeding alteration of the length of the waves of the transmitter shall take place by the switching oil of the detector from the transmitter.

This improved arrangement of transmitter will now be more particularly described with reference to the accompanying drawings, in which:

Figure l is a diagrammatic view of the new arrangement in combination with a simple transmitter in which the sparking device is arranged directly in the aerial wire. Figs. 2 and 3 are modifications of Fig. 1, and Fig. 4 shows the use of the invention in a transmitter which is fed from a closed cXciter circuit.

which a wire 2 leads to the receiver apparatus which is switched off by means of a switch when transmitting from the honn station. 3 is the sparking device which is compescd of several small spark gaps to each of which a small condenser is inserted in parallel with charge potential over the se arate spark gaps. 4 and 5 indicate a variaiile condenser and a variable self-induction for altering the length of the waves of the transmitter, 6 is an earth connection or a wire which connects the aerial conductor to earth or an equivalent electrical eounterpoi'se; 7 is a switch by means of which the detector 8 may be switched into the transmitter circuit. This detector is of such a kind that it enables alterations of amplitude of theelectric waves transmitted to it, to be ascertained, that is to say a so-called integral detector. In the present case an electrolytic cell is employed abattery 9 constantly flows, which is connected with the detector by means of chokin coils 10. A telephone 11 also lies in the loca circuit by means of which telephone all alterations in the electric behaviour of the cell may be ascertained. A comparatively large condenser 12 variable in its capacity, lies in parallel with the cell.

With the object ottuning the transmitter to the length of the waves radiated from a distant transmitter the procedureis as-follows: The sparking device is first short circuitedby means of the switch 13, and then by means ofthe switch 7 the cell 8 is switched on into the transmitter circuit with the condenser 1'2 lying parallel with the cell. The condenser 12is then adjusted to an average capacity and the condenser 4 and the selfinduction 5 altered until the maximum pitch or strength of sound-is obtained in the telephone 11. is then enlarged and now the condenser 4 and self-induction 5 are suitablyaltered until again the greatest strength of sound in the telephone takes place. The operation is continued in this manner under constant enthe object of uniformly distributing the The capacity of the condenser 12' In Fig. 1, 1 is the aerial conductor from for this object, over which cell the current of shown in Fig. 3.

' alteration of the self-induction 5.

'mediary of the switch 14. During the trans- The condenser 15 must in this case be as '18, 19, must be tuned to the length of the largement of the capacity of the condenser 12-, whereby finally a-very sharp tuning ofthe transmitter to the length of the waves of the distant transmitter is obtained. Then the detector is cut oil from the transmitter by means of the switch 7 and the circuit is again closed over the wire 1 1 and the switch 13 opened. .The transmitter is now ready for work, so that signals or" the just determined length of waves may be immediately sent.

Instead of breaking the transmitter circuit by the use ofa switch 7 at one place, and switching on the detector into this place, the switching of the detector into the trans mitter may be operated without such breakmg of the transmitter circuit, in the manner shown in Fig. 2, the detector being placed in parallel to-the-sparking device by the intermission of signals the switch 14 is in the position of repose shown.

It in tuning the transmitter, the capacity of the condenser 12 has not become large enough to be able to be neglected relative to. the capacity of the aerial conductor andthat of the condenser 4, a small alteration of the tuning value takes place when the celland the condenser 12 are switched oil, in the direction of an enlargement of the length of the. waves of the transmitter. In order to avoid this it is preferable to employ the connections In this arrangement the electrolytic cell 8 with a previously inserted condenser 15, is switched on by means of the switch 16 in parallel to the variable condenser 4 lying in the transmitter circuit.

small as possible and, in the tuning of theaerial wire, the condenser 4 must not be altered, or at east only gradually altered, whilst the fine tuning must take place by the After the tuning has taken place it is then only necessary to switch off the cell and the condenser- 15. by-means of the switch 16in order to make the transmitter ready for dispatching messages. The arrangement shown in Fig. 3 is more particularly employed when the condenser 4 lying in the aerial conductor is a comparatively large one, whilst the arrangement shown in Fig. 1 is only employed when the condenser 4 is a comparatively small one.

In using a transmitter which is fed from a closed exciter circuit (Fig. 4-), a similar ar rangement may Y be adopted as was de-' scribed with reference to Figs. 1 and 3 but the circumstances are not so simple as in those cases. In fact it does'not sufiice here only to tune the open transmitter circuit alone but also the closed exciting circuit 17,

waves radiated from the transmitter. This is done in the simplest way by the open transscribed in'connection with Fig. 3, andthen the closed oscillation circuit altered'by variations of the self-induction 17, until a current meter inserted'in :the transmitter, for instance, a hot wire instrument 20, indicates a maximum oscillation. The desired coupling between exciting and transmitting circuits is established by'altering the coils common to both circuits of the self-induction coil 17. By this means the number of inherent oscillations of the aerial conductor is indeed somewhat alteredbut this alteration of the self-induction of the aerial conductor is so small by reason of the self-induction 5 remaining constant and the self-induction. which is distributed in the aerial conductorbeing so small that itmay be practically dis regarded. 7

During. the tuning of the transmitter circuit and also during the transmission, it suflices to short circuit thecurrent'meter 20 by means of the switch 21.

What I claim as my invention and desire to secure by Letters Patent of the United States is: l

for tuninga transmitter to a distant sending station, said meanscomprising the coihbination of an open oscillation circuit having an aerial with an earth or equivalent connection, meansin said circuit for varying its in' herent period, a detector responding to current intensities, means for connecting and disconnecting said detector in said circuit, and means whereby electrical ostillaf'ions may be produced in said circuit.

fortuning a transmitter to a distant sending tion of the transmitter, means for varying the inherent periods of the transmitter, a detector responsive to current intensities, means for connecting and disconnecting said yarying means, and means whereby electrical mitter.

station, said means comprising the .combina tion of the transmitter, means for-tuning the transmitter, a detector-responsive to current necting the detector Withthe transmitter and its tuning means, and a sparking device for the transmitter. a 1

4. In wireless telegraph apparatus, means for tuning a transmitter to a distant sending station, said means comprising the combinasame, a detector responsive to current intensities, a capacity, means for connecting the capacity in 'parallel with the detector, means for connecting and-disconnecting the mitter being first tuned in the manner de- 7 detector with the transmitter and its tuning Y 1. In wireless telegraph apparatus, means 2: In wireless telegraph'apparatus, means detector with the transmitter and its periodp 3. In Wireless telegraph apparatus, means i I for tuning atransmitter to a distantv sending intensitiesym eans for connecting and discontion of the transmitter, means for tuning the station, said means comprising the combinaoscillations may be produced in the transthe same, a sparking device for the trailsmitter, a detector responsive to current intensities, means for conneetingand disconnecting the detector with the transmitter and its tuning means, and in parallel with the sparking device.

6. In Wireless telegraph apparatus, means' for tuninga transmitter to a distant sending station, said-means comprising the combina tion of the transmitter, tuning devices for the transmitter, a detector responsive to current intensities, means for eo-oPeratively connecting the detector and said tuning means With-[thetransmitterfor tuning the same and fordis'conneeting the detector after the transmitter is tuned.

7. In Wireless telegraph apparatus, means for tuning a transmitter to a distant sending I I I l station, said means comprising the trans- 25 mitter, a spark device and tuning means for the transmitter, a detector responsive to cur: 7

rent intensities, means for connecting and disconn'ecting'the detector with the trans-- mitter and tuning means, and in parallel to the spark gap.

' 8. In wireless telegraph apparatus, means for tuning a transmitter to a distant sending station, said means comprising the eon1l.ination of a transmitter, a spark device in series therein, tuning means in the transmitter, a detector responsive to current intensities, means for connecting and disconnecting the detector with the transmitter and tuning means, and means for shunt ing the spark device When the detector is connected.

In witness whereof, I hereunto sultscrihe my name this ninth day of June A. D. 1905.

GEORG VON ARGO. Witnesses: HENRY HAsPER,

VVOLDEMAR HAUPT. 

